Jan. 30, 2012 -- Mothers who are more supportive of their young children through the stresses and frustrations of life are doing more than heading off full-blown tantrums. They may actually be encouraging healthy brain development, a new study shows.

For decades, researchers have observed that the brains of animals who are nurtured early in life look different than those of animals that are not given similar care. Studies have also found that nurtured animals tolerate
stress better than animals that are raised without support.

"Parental support, particularly in early childhood, is a very, very powerful force in a child's life," says researcher Joan L. Luby, MD, a professor of child psychiatry at the Washington University School of Medicine in St. Louis, Mo. "It's a very positive, powerful force."

Tracking the Impact of Support on Young Brains

The study followed 92 children from preschool into their grade-school years.

For the study, Luby and her team videotaped each parent and child while they completed an experiment called "the waiting task."

Children, who were between the ages of 4 and 7, were presented a brightly wrapped gift, but were told they had to wait eight minutes before they could open it.

In the meantime, moms were asked to fill out a stack of forms.

"It really simulates a real-life parenting situation that people often face. You're cooking dinner and your child is throwing a tantrum, and how do you juggle that?" Luby says.

"The maternal support had to do with how much positive parenting the parent showed: how much they reassured the child, how much they helped regulate the child when the child made bids that they needed that gift," she says.

Later, trained assistants scored the moms on how well they helped their children through the stress of the task.

Researchers continued to follow the children, and when they were between the ages of 7 and 13, their brains were scanned using magnetic resonance imaging (MRI).

Researchers were particularly interested in the size of a comma-shaped brain region called the hippocampus, which plays a role in memory and how we handle stress. Hippocampus size has been linked to factors such as stressful life events and depression severity.

Support Bolsters Brain's Learning Memory Centers

Among the 51 kids in the study who had no symptoms of depression as preschoolers, those who got more support from their moms as they completed the waiting task had larger hippocampi seen in later scans.

That brain region was about 9% smaller, however, in non-depressed kids who got little or no help dealing with their stress and frustration as they waited to open the gift.

"What maternal support is doing in the kids who are not depressed is reducing their exposure to stressors, which is helping them. It's reducing the impact of stress," says Ian H. Gotlib, PhD, professor of psychology at Stanford University. Gotlib studies the biological basis of depression, but was not involved in the research.

"It's a great study," says Gotlib, who is also director of the university's Mood and Anxiety Disorders Laboratory. "It opens up some really interesting possibilities for intervening."

Depressed Kids May Not Respond as Well

Among the 41 kids who had symptoms of depression as preschoolers, maternal support didn't appear to be as helpful, however. Depressed kids with high support from their mothers still had smaller hippocampi compared to non-depressed kids with highly supportive mothers. However, the size was only 6% smaller.

Researchers say that may be because the positive effect of maternal support may be countered by the negative effect of depression.

"Maternal support is helpful in depressed children, but it doesn't have as powerful an effect because their brain development is being brought down by other forces," Luby says.

But Gotlib says that doesn't mean kids who are showing signs of depression early in life can't be helped.

"That, to me, just kind of emphasizes how important it is to get these kids treated, or to teach them coping strategies, to do something to reduce those depressive symptoms," he says.

Gotlib says it could be that early treatment may help depressed kids get to a place where they can also respond well to love and support.

In either case, he says the message for parents is clear: "You don't lose anything by trying to be more supportive if you're a mom. In both groups, maternal support is better than not." Although nearly all participants in the study were mother-child pairs, the authors note that they would expect the same findings with any primary caregiver.